Active optical imaging technology has greatly expanded the boundaries of human vision and achieved rapid progress in many emerging applications, such as long-range imaging [1]}, [2]}, underwater imaging [3]}, [4]}, non-line-of-sight imaging [5]}, [6]}, [7]} and microscope imaging [8]}, [9]}. In recent years, light detection and ranging (LiDAR) [10]} has secured a dominant position in the field of active optical imaging. Conventional LiDAR system requires more than \(10^{3}\)  signal photons per pixel for accurately imaging a 3D scene [11]}. However, such large number of signal photons can not be collected in photon-starved scenarios where optical flux and integration time are limited. Since single-photon avalanche diodes (SPADs) [12]} provide extraordinary optical sensitivity and picosecond (\(ps\) ) time resolution, SPAD-based LiDAR, also named single-photon LiDAR, has been designed to fully exploit few or even one signal photon per pixel to precisely capture the 3D structure information in photon-starved scenarios, such as extremely distant and poorly reflective surfaces [13]}, [14]}, [1]}.
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